Quick answer: Borofloat 33 With Blind Holes covers Borofloat 33 (CTE 3.25 x 10^-6 /K, 350 nm – 2.0 um); depth control +/-0.05 mm, flat or radiused bottom. Prototypes ship in 5-10 working days.
When a drawing calls out Borofloat 33, three numbers matter before any machining starts: CTE of 3.25 x 10^-6 /K, service temperature to 450 C continuous, and a transmission window of 350 nm – 2.0 um. borofloat 33 with blind holes here begin with those numbers and end with dimensional reports.
Specifications at a glance
| Material | Borofloat 33 (SCHOTT float production, wafer grade) |
|---|---|
| Thermal expansion (CTE) | 3.25 x 10^-6 /K |
| Service temperature | 450 C continuous |
| Transmission range | 350 nm – 2.0 um |
| Density | 2.23 g/cm3 |
| Knoop hardness | 480 kg/mm2 |
| Refractive index | 1.471 @ 587 nm |
| Stock thickness | 0.70 – 25.4 mm |
| Maximum blank size | 500 x 500 mm |
| Feature | Blind Holes |
| Capability | depth control +/-0.05 mm, flat or radiused bottom |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
What the process holds
Beyond this page, Borofloat 33 routinely runs through drilling, polishing, coring, lapping in our shop – most real parts combine two or three of these steps.
These features are produced by ultrasonic machining or cnc machining. Capability: depth control +/-0.05 mm, flat or radiused bottom. Design rule worth copying onto the drawing: leave at least 30% of thickness under the bottom.
Specification advice
Three items decide most of the cost and lead time on this work:
- Material note: float tin side must be tracked when parts see coating or bonding steps.
- Feature rule: leave at least 30% of thickness under the bottom.
- Over-specification is the quiet budget killer: a 20/10 scratch-dig face costs roughly three times an 80/50 face, so grade each surface individually.
For the complete framework, see the tolerance design guide and the holes and edges design guide.
Typical applications
Orders for borofloat 33 with blind holes cluster in optical sensors (sensor windows, filter caps, lens covers); led packaging (groove covers, phosphor carriers, package windows); machine vision (camera windows, ring-light diffusers, calibration plates). Background reading on the underlying material science: SCHOTT BOROFLOAT product page.
Dimensions still moving? Configure this part live in the 3D + 2D builder below, or open the full custom glass machining 3D + 2D builder to start from a blank canvas.
Useful companion pages: 4 inch Borofloat wafers, Borofloat 33 selection guide, custom ITO glass.
Common questions
Is there a minimum order for borofloat 33 with blind holes?
No. Single prototypes are accepted, and pricing steps down at 10, 100 and 1,000 pieces.
How fast can prototypes ship?
Machined prototypes ship in 5 – 10 working days. Coated or bonded parts add 1 – 2 weeks depending on queue slots.
What files do you need for a quote?
A dimensioned PDF plus DXF or STEP geometry. If only a sketch exists, our drawing review service formalizes it before quoting.
Do parts ship with inspection data?
Dimensional reports, surface certificates and material certs per melt are available; specify the level on the RFQ.
What tolerances are achievable on Borofloat 33 parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Float tin side must be tracked when parts see coating or bonding steps.
Specifications on this page were last reviewed by our engineering team in September 2026.